The invention relates to improvements in skis, snowboards and like and more particularly, to a method and apparatus for adjusting the flexion and torsion characteristics at specific locations on the ski or snowboard.
The present invention is directed to skis and ski type devices which are used in a wide range of recreational and profession athletic endeavors, such as snow skiing and snowboarding, water skiing and even to a limited extent skateboarding. All of these activities involve an individual riding a substantially flat board, herein referred to as a ski or snowboard, across a surface. One of the challenges of these activities is the ability to control the direction of the ski at various speeds and under a wide range of conditions. Snow skiing and snowboarding are well known examples which challenge individuals on both a professional and recreational level.
Skis and snowboards are typically constructed of a wood or synthetic core material with a reinforcing material, such as an epoxy fiberglass, laminated to the core material. The type and arrangement of the reinforcing materials is selected in order to provide the desired flexion and torsion characteristics. The reinforcing material can also include well known materials such as graphite, carbon and/or KEVLAR which can be used to increase the stiffness without significantly increasing the weight of the board. The base or bottom of the ski or snowboard that rides on the snow is typically constructed of a sintered polyethylene material, sold under the trademark P-TEX, and is laminated or molded to the bottom of the reinforced core. Steel edges are secured to the lateral side edges, typically co-planar with the bottom surface of the base. Threaded inserts or a retention plate are mounted in the core to facilitate the attachment of bindings.
The top surface of the board can be completed by either adding side walls and laminating a top sheet such as ABS (Acrylonitrile Butadiene Styrene) to the top of the reinforced core (sandwich laminated construction) or by wrapping the top sheet material around the core, right to the metal edges (cap construction). Cap construction is more aesthetically pleasing and produces a board having stiffer flexion and torsion characteristics.
Snowboarding is distinguished from skiing in that snowboarding involves the use of what may be termed a single ski that is substantially wider that a traditional ski, with both feet supported on the single ski. While the skier's feet point in a direction parallel to the longitudinal axis of a conventional ski, the orientation the snowboarder's feet with respect to the longitudinal axis can be varied to suit the rider and the snowboarding discipline. For example, freestyle riders typically orient their rear foot perpendicular to the longitudinal axis of the snowboard and orient their front foot pointing slightly forward at approximately 5 to 20 degrees from perpendicular to the longitudinal axis of the snowboard, and giant slalom riders typically orient both feet pointing forward by as much as 45 to 90 degrees from perpendicular to the longitudinal axis of the snowboard. Theses stances and styles are intended to facilitate control of snowboard while performing different types of snowboarding maneuvers.
A conventional skier stands facing forward and controls his or her direction by transferring weight laterally, between two edges of two separate skis. The snowboarder stands sideways, with either the left foot forward (in a regular stance) or the right foot forward (in a "goofy" stance), and controls the operation of the snowboard by applying pressure to the toe side edge or to the heel side edge, as well as by controlling the edge pressure of the front foot with respect to the rear foot. Thus the forces applied to the snowboard in carving turns are different in certain aspects from the forces applied to a pair of skis to carve the same turn.
It is generally known in the art that the performance of a snowboard or a ski is dictated by the size and shape, as well as the flexion and torsion characteristics, of the board for a given user and snow conditions. Thus, longer snowboards and skis are usually given to taller and heavier riders. Longer snowboards and skis are preferred for higher speeds and wider turning and are considered by some to be easier to use in deep snow. Shorter snowboards and skis are preferred for making quicker turns and for performing tricks. Stiffer snowboards and skis are preferred for skiing on hard packed snow and ice because they hold their edge better. Softer snowboards are preferred for skiing on fresh powder. Other characteristics such as the length and shape of the side cuts of the lateral edges also influence the performance of the snowboard or skis.
While skis tend to be symmetrical in shape with respect to their longitudinal axis, there has been a trend in snowboarding to provide a snowboard with an asymmetrical shape. The purpose of the asymmetrical shape is to accommodate the fact that the snowboarder's toes can be positioned ahead of his heels on the board. Thus, in order to provide for more even performance regardless of whether the snowboarder is making a heel side turn or a toe side turn, the heel side edge is shifted or offset toward the rear of the board.
Typically, conventional skis and snowboards are designed to perform well under a particular set of snow conditions. Thus, a professional or an expert may have several pairs of skis or snowboards including for example, a stiffer snowboard or pair of skis for skiing on hard packed snow and a softer snowboard or pair of skis of use in soft powder. The average person who cannot afford to own more than one pair of skis or one snowboard, will only have one general purpose pair of skis or snowboard which presents a compromise in stiffness and in performance. This snowboard will not perform well on either hard packed snow or fresh powder.
There have been several attempts to provide a means for changing the flexion and torsion characteristics of skis and snowboards. U.S. Pat. No. 5,573,264 to Deville et al., discloses applying a reinforcement layer to the top of the snowboard. The flexion and torsion characteristics of the snowboard are changed by using different reinforcement materials or by adding or subtracting additional reinforcement layers. U.S. Pat. No. 4,592,567 to Sartor discloses a similar method for changing the stiffness of a snow ski, using removable battens or inserts.
One disadvantage of these prior art devices is that, like the general purpose snowboard design, they only provide for changing the flexion and torsion characteristics of the ski or snowboard by a predefined amount in a general area, typically the area in front of the binding and/or the area in back of the bindings. Thus, the rider can only influence the flexion and torsion characteristics of the ski or snowboard in a limited amount and cannot limit that influence to a particular isolated portion of the board. In addition, the limited adjustment provided by these prior art devices cannot be performed by the rider quickly and easily on the slope.
Accordingly, it is an object of this invention to provide a method and apparatus for adjusting the flexion and tension of a snowboard or ski.
It is another object of this invention to provide a method and apparatus for precisely adjusting the flexion and tension of a snowboard or ski.
It is a further object of this invention to provide a method and apparatus for quickly and easily adjusting the flexion and tension of a snowboard or ski on the slope.
It is yet another object of this invention to provide a method and apparatus for adjusting the flexion and tension of a snowboard or ski at locations along the length of the snowboard or ski.